I’m interested in a (cheap) disc brake piston press, and am taking a look at AliExpress … There seem to be two different designs that seem to achieve a similar outcome. Any advice on which of these may be the better option? Or advice/suggestions on other options?
The press is to be used with Shimano road calipers, as well as dual piston Shimano and Magura calipers.
TIA. 
Hello,
I have the second one in use (the one with the round washers), mostly with Shimano Road brakes, and I am quite happy with it. I have seen that they also make a version with more squared surfaces for MTB (?), but no first-hand experience there.
Simple.
Don’t buy stuff from AliExpress.
Hey, entitled to your opinion, but keep it to yourself if it adds nothing to the discussion other than jingoism.
Hi Simon,
I’ve got that green one - which I got for a substantial cost savings over the SRAM original. It was a debate for me as well, between both options up there. I went for the green one, because the black one relies on magnets to hold both opposing pieces (where the washers are) together. The rationale being that once the pads have been spread, there’s really only minimal tension holding the opposing pieces in place, which would likely fall right off. That, and the fact that the device is a little shorter, which might make usage a little less convenient.
The green one, is a little longer and I’ve found that the knob at the end is more easily accessible, and made largely of aluminium bits that would be less prone to rusting. The downside, is that the sliding piece can be wholly unscrewed/detached from the black knob at the end of its travel, but shouldn’t pose any problems in normal usage, since you’d rarely need the slider to be in that position anyway.
“don’t buy from AliExpress” adds to every discussion about stuff from AliExpress.
Most of the stuff offered there is bad quality and/or plagiate.
I had the green one, it’s fine though unfortunately broke on some particularly stiff pistons! I would say it’s ok if you are careful in those circumstances. There is also a narrower blue one that’s more suited Shimano. I have that also and it’s still working.
I have a mix of well known brands and AP stuff in my workshop and both can compliment each other well.
rubbish, but then as you don’t buy from AliExpress, clearly you have no idea.
I have the top one, works really well. Make sure you insert the right way round not to foul on your frame.
I have one of these and it’s great. IMO this is the best low cost option for this task.
I believe Dave Rome did a writeup on these - personally I think the 3d printed wedges from cmh printed designs can’t be beat value/usability-wise
https://escapecollective.com/threaded-30-one-more-new-tools-day-for-the-year/
I have the bottom one made by Sumart after seeing it mentioned by @Dave_Rome.
I don’t know if Sumart version is the original. In general, it works really well on my Shimano and SRAM road brake calipers. The only issue I encountered was on my second use, the dial got stuck and forcing it to rotate stripped bits of the bolt. It’s still usable though.
I have the green one with a different handle. It’s great! The only downside is it doesn’t necessarily fit all brakes (although most if not all two piston brakes will be ok), therefore usage on some four piston brakes is not ideal (pushing apart two pistons fully and two pistons partially at a time) or straight impossible.
Anyone has a tip for a piston spreader for four piston brakes?
The alibaba ones are lower quality and rip off someone else’s design, in comparison to the original designs though at a substantial cost savings. If they would have one for 4 piston mountain bike brakes I like those 3d designs.
Nice bit of kit. Shame about the £16 carriage to the UK
@carytb The 3d print files are public. Print it out at your local maker space for pennies.
Use a plastic tyre lever. Never had a problem.
You having never had a problem could be indicator of skill, or luck, and certainly doesn’t suggest it’s the best approach.
While it’s probably fine most of the time (I’ve done similar), the risk of the tyre lever approach is that the piston gets misaligned. It also assume that someone has, or can find, a tyre lever that will fit in the brake, and that the pistons haven’t been pushed out so far that the tyre lever will get between them.
The piston pusher tools, if designed correctly, will push the pistons in square, and will fit between them even if fully pushed out.
